Electric-drive mechanism



Nov. 6, 1923 `v 1,473,167

C. S. WEYANDT ELECTRIC DR-IVE MECHANISM Filed Nqv. 2C, '1919 2 Sheets-Sheet 2 Patented Nov. 6, 1923.

y UNITED STATES PATENT foi-Fica CARL S. WEYANDT, OF PITTSBURGH, PmNSYLVVANIA, ASSIGNOB TO' CENTRAL ELEC- TRIO TOOL COM'PANY, 0F PITTSBURGH, PENNSYLVANIA, A CORPORATION' 0F PENNSYLVANIA.

ELECTRIC-DRIVE MECHANISH.

purposes wherein it is found applicable, and

the invention'has for its object to provide a v drive mechanism, in a manner as hereinafter set forth, including means to set up an elec- -trical circuit at proper intervals of time through one solenoid for reciprocating an element, i. e., the solenoid core which constitutes a plunger, to impact a tool to operate the latter. A further object of the invention is t ated through the medium of-a magnetic cir cuit having an air gap within the coil there-- of, whereby the energy is concentrated `at the air gap and there is provided an outlet for passing the energy with minimum losses to the recepirocatory element or the core of the solenoid constituting a plunger. This form of ma netic circuit gives a high power factor and e iminates excessive heating while permitting theradiation surface of the coil to be reduced to a minimum.

A further object of the invention is to provide an electric drive mechanism operated through the medium of a magnetic circuit having an air gap Within the coil thereof and to position the air gap in close proximity to the solenoid c'ore or plunger, thereby reducin magnetic leakage.

A firther object of this invention is to provide an electric drive mechanism whereby the reciprocator)r core of the'solenoid is utilized to engage contacts to energize and deenergize the solenoid for the purpose of changing the direction of travel of the A iurther object of the invention, is to so arrange, in a manner as hereinafter set forth, the contacts, plunger, magnetic circuit and is to be understood that it is adapted for any v provide an electric drive mechanism oper! air gap, that maximum acceleration 0f the plunger is attained'.

Further objects of this invention are to provide an electric drive mechanism, which is simple in its construction and arrangement, compact, strong, durable, having the size thereof reduced toa minimum, convenient and efficient in its use, readily assembled and comparatively inexpensive to. manufacture.'

With the foregoing and other objects in view the invention consists of the novel construction, combination and arrangement of parts herein specifically described and illustrated in the accompanying drawings, wherein is shown an embodiment of the invention, but it is to be understood that changes, variations and modifications can be resorted to which come withinthe scope of the claims hereunto appended.

In the drawings forming a portion of this specification and wherein like numeralsy of reference designate corresponding parts throughout the several views:

' Figure 1 is a longitudinal sectional view of an electric drive mechanism made in accordance with this invention and showing the adaption thereof in connection with an electric hammer.

Figure 2' is a diagrammatic view illustratthe device.

Referring to the drawings in detail, wherein the drive mechanism is illustrated, b way of example, in connection with an eectric hammer, they casing of the mechanism is .formed of any suitable material andcomprises a head or handle portion, an end or tool receiving portion and an intermediate portion, but it is to be understood that the arrangement of the casing can be as desired. The end portion consists of a socket member l0, which receives the tool to be o rated, and the member 10, has formed inte ral therewith and projecting therefrom a co lar ll, which terminates in a flaring-extension l2, provided with a. shoulder 13, and internal threads 14. The head comprises a hollow conical shaped member 15,- havin a shoulder 16 and internal threads 17 .Y lie member 15 is formed with a'pair -of open- 'ings 18 and 19, the former being of greater diameter than the latter.` Formed integral with the member 15 is a hollow handle 20 havin the end thereof which is integral with t e member 15 re 'ster with the opening 18. The wall 0 the opening 19 is threaded and the handle 20-has an openin 21 with the wall of the .latter threade Seated in the' openin 19 is a plug 22 for the leading-in-Wires, an mounted in the opening 21 is a push-button or switch 23. The intermediate portion of the casing' is formed of two spaced annular members 24', 25 which are connected together by a cou ling band 26. The member 24 engages wit the threads 14 and the member 25' with the threads 17.- B the arrangement set forth the casing of t e mechanism can be assembled and disassembled quickly when occasion so requires. The tool is not shown mounted in the member 10, but any form of tool, which can be o erated on, 1s employed.

Mounted in t e casin of the mechanism is a longitudinally exten ing cylindrical tube 24 of non-magnetic material formed at its forward end with a pair of slots 25 and at its rear end with a pair of slots 26. At the forward end of the tube 24, are pivotally mounted oppositely disposed sprlng con? trolled contacts 27, two in number, and which normally project through the slots 25, into the tube 24, and in the path of the core of the solenoid, to be hereinafter referred to, said core forming the reciprocatory element of the mechanism and constituting the plunger which acts on the tool mounted on or rather in the member 1.0. At the upper or rear end of the tube 24, are pivotally mounted oppositely disposed spring controlled contacts 28, two in number, which normally project through the slots 26, into the tube 24, and in the path of the core of the solenoid referred to above. c

Mounted on the tube 24, intermediate the ends thereof, is a solenoid consisting of the coil 29 and the core 30, the latter being the reciprocatory element of the mechanism and constituting a plunger which reciprocates in iiehtube 24. Surrounding the coil 29 are -s a dicated at31.. They are so sha d as to rovide air gaps 32 at that lsi e thereof arin on the tube 24. The cores 31 enclose t e coil 29 and provide magnetic circuits formed with air a s. The air gaps 32 are arranged aroun t e central portion of the tube or barrel 24 and may be regarded in eiect as an annular gap. W1thin the tube 24 at the forward end thereof is arranged a coil spring 33 to take vibration oi the handle 20 during the reciprocation of the core or lunger 30.

he arrangement of the conductors for forming the circuit to provide for the reci vocation of the core or plunger 30 is as fo lows The leading-in-wires are indicated at 1,

ped cores of laminated form, as in-` 2, 3 and 4, and are carried through the casing' of the mechanism in the plug 22. The wire 1 leads to one of the contacts 27 and the wire 4 leads to the other Contact 27. The wire 2 leads to the coil 29, and the wire 3 t0 one-of the contacts 28. Leading from the other contact 28 to the wire 4 is a wire 6. Leading from the switch`23 to the coil 29 is a wire 7 and leading from the switch 23 to the wire 4 is a wire 8.

The operation of the drive mechanism is as follows--d Associated with the drive mechanism is a magnetic switch including two pairs of contacts, the contacts of ,one pair are indicated at 34, and the c'ontacts of the other pair at 35. The arm 36 operated by the coil 38 carries the lower contact 34 and the arm 37 operated by the coil 39 carries the lower contact 35. The magnets 38 and 39 are connected together by a conductor 42, from which leads a conductor 43 to source. The wire or conductor 4 leads to source. The wire or conductor 2 leads to one of the contacts 35. The conductor 1 leads to magnet 39 and the conductor 3 leads to magnet 38.,

The conductor 43 is connected with the conductor 41.

Itwill be assumed that the plunger is in position, as shown in Figurel 2, having contact enga ement with the pair of contact arms 27, w ich complete an electrical circuit from the source of supply through conductors 4 y and 1 and magnet 39. The magnet 39 beingenergized closes contacts 35 closing an electrical circuit through conductors 2, 7 8 and 4 and coil 29. AThe coil 29 now being energized induces a flux in the magnetic -circuit whereby the plunger is drawn into the air gap. The engagement between the plunger and contacts 27 is maintained until maximum acceleration has been imparted to the plunger, at which instant the contacts 27 are opened whichA opens contacts 35 and opens the circuit throu h the coil 29. The plunger however dueto inetic energy passes to the other end of the tube 24 and engages contacts 28 thus'making an electrical circuit from the source through conductors 3,y

4 and 6, magnet 38 to source. The magnet 38 now being energized closes contacts 34 and energizes coil 29 through conductors 2, 7 8 and 4 which pulls the plunger in the o posite direction until its engagement with tlrie contacts 27 for the purpose heretofore stated.

The langern in its travel strikes against the too which may be a chisel, weldin die or an other instrument upon which a low may e used to produce work.

What I claim is:

1. In an electric hammer, current supply.

lines, a sin le solenoid, a magnetic core' reciprocable t erein, and contacts cloaable by the core at the end of each stroke of the core to eiect the next stroke, and openable by the core when the latter reaches the central part of the solenoid.

2. In an electric hammer, current supply lines, a single solenoid, a magnetic core reciprocable therein, and contacts closable by current through the core at the end of each stroke of the core to elect the next stroke, and openable by the core when the latter reaches the central part of the solenoid.

3. In an electric hammer, current supply lines, a single solenoid, a magnetic core reciprocable t erein, contacts closable by current through the core at the end of each stroke of the core to effect the next stroke, and openable by the core when the latter reaches the central part of the solenoid, and switching means operated by current through said contacts and connecting the solenoid to the said lines.

4. In a reciprocating apparatus, a solenoid, means to provide a magnetic circuit provided with an air gap, said circuit coacting with the solenoid, a core arranged to reciprocate through the solenoid to open and close the gap thereby opening and closing the magnetic circuit, a switching element in circuit with the solenoid for causing the energization and de-energization thereof when the gap is closed and opened by the core, and means engaged by the core and in connection with the latter for closing an operating circuit to throw said switching element into operation during the reciprocation of the core.

5. In a reciprocating apparatus', a solenoid, means to provide a magnetic circuit co-acting with the solenoid,'said circuit hav- 4 ing an air gap, means to energize and deenergize said solenoid, and a core arranged to reciprocate through said solenoid for opening and closing said gap, said core during its reciprocations throwing said means for energizing and de-energizing the solenoid into and out of ^peration to alternately energize and cie-energize said solenoid to cause reciprocations of the core.

In testimony whereof I affix my signature.

CARL S. WE YANDT. 

